Albert Einstein
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Albert Einstein
Albert Einstein in 1921
Born
14 March 1879
Ulm, Kingdom of
Württemberg,German Empire
Died
18 April 1955 (aged 76)
Princeton, New Jersey, United States
Residence
Germany, Italy, Switzerland, Austria,
Belgium, United States
Citizenship
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Fields
Institutions
Kingdom of Württemberg (1879–
1896)
Stateless (1896–1901)
Switzerland (1901–1955)
Austria-Hungary (1911–1912)
German Empire (1914–1918)
Weimar Republic (1919–1933)
United States (1940–1955)
Physics
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Swiss Patent Office (Bern)
Alma mater
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University of Zurich
Charles University in Prague
ETH Zurich
Caltech
Prussian Academy of Sciences
Kaiser Wilhelm Institute
University of Leiden
Institute for Advanced Study
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ETH Zurich
University of Zurich
Thesis
Folgerungen aus den
Capillaritätserscheinungen (1901)
Doctoral advisor
Alfred Kleiner
Other academic
advisors
Heinrich Friedrich Weber
Notable students
Known for
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Abdul Jabbar Abdullah
Ernst G. Straus
Nathan Rosen
Leó Szilárd
Raziuddin Siddiqui[1]
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General relativity and special relativity
Photoelectric effect
Mass-energy equivalence
Theory of Brownian Motion
Einstein field equations
Bose–Einstein statistics
Bose–Einstein condensate
Bose–Einstein correlations
Unified Field Theory
EPR paradox
Notable awards 
Nobel Prize in Physics (1921)
Matteucci Medal (1921)
Copley Medal (1925)[2]
Max Planck Medal (1929)
Time Person of the Century (1999)
Spouse
Mileva Marić (1903–1919)
Elsa Löwenthal (1919–1936)
Children
"Lieserl" (1902–1903?)
Hans Albert (1904–1973)
Eduard "Tete" (1910–1965)
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Signature
Albert Einstein (/ˈælbərt ˈaɪnstaɪn/; German: [ˈalbɐt ˈaɪnʃtaɪn] ( listen); 14 March 1879 – 18 April
1955) was a German-borntheoretical physicist and philosopher of science.[3] He developed
the general theory of relativity, one of the two pillars ofmodern physics (alongside quantum
mechanics).[2][4] He is best known in popular culture for his mass–energy
equivalenceformula E = mc2 (which has been dubbed "the world's most famous equation").[5] He
received the 1921 Nobel Prize in Physics"for his services to theoretical physics, and especially
for his discovery of the law of the photoelectric effect".[6] The latter was pivotal in
establishing quantum theory.
Near the beginning of his career, Einstein thought that Newtonian mechanics was no longer
enough to reconcile the laws ofclassical mechanics with the laws of the electromagnetic field.
This led to the development of his special theory of relativity. He realized, however, that the
principle of relativity could also be extended to gravitational fields, and with his subsequent
theory of gravitation in 1916, he published a paper on the general theory of relativity. He
continued to deal with problems of statistical mechanics and quantum theory, which led to his
explanations of particle theory and the motion of molecules. He also investigated the thermal
properties of light which laid the foundation of the photon theory of light. In 1917, Einstein applied
the general theory of relativity to model the large-scale structure of the universe.[7]
He was visiting the United States when Adolf Hitler came to power in 1933 and, being Jewish,
did not go back to Germany, where he had been a professor at the Berlin Academy of Sciences.
He settled in the U.S., becoming an American citizen in 1940.[8] On the eve of World War II, he
endorsed a letter to President Franklin D. Roosevelt alerting him to the potential development of
"extremely powerful bombs of a new type" and recommending that the U.S. begin similar
research. This eventually led to what would become the Manhattan Project. Einstein supported
defending the Allied forces, but largely denounced the idea of using the newly discovered nuclear
fission as a weapon. Later, with the British philosopher Bertrand Russell, Einstein signed
the Russell–Einstein Manifesto, which highlighted the danger of nuclear weapons. Einstein was
affiliated with the Institute for Advanced Study in Princeton, New Jersey, until his death in 1955.
Einstein published more than 300 scientific papers along with over 150 non-scientific
works.[7][9] His intellectual achievements and originality have made the word "Einstein"
synonymous with genius.[10]
Biography
Early life and education
See also: Einstein family
Einstein at the age of 3 in 1882
Albert Einstein in 1893 (age 14)
Einstein's matriculation certificate at the age of 17, showing his final grades from the Argovian
cantonal school (aargauische Kantonsschule, on a scale of 1–6, with 6 being the best mark)
Albert Einstein was born in Ulm, in the Kingdom of Württemberg in the German
Empire on 14 March 1879.[11] His father was Hermann Einstein, a salesman and
engineer. His mother was Pauline Einstein (née Koch). In 1880, the family moved
to Munich, where his father and his uncle foundedElektrotechnische Fabrik J.
Einstein & Cie, a company that manufactured electrical equipment based on direct
current.[11]
The Einsteins were non-observant Ashkenazi Jews. Albert attended a Catholic
elementary school from the age of 5 for three years. At the age of 8, he was
transferred to the Luitpold Gymnasium (now known as the Albert Einstein
Gymnasium), where he received advanced primary and secondary school education
until he left Germany seven years later.[12] Contrary to popular suggestions that he
had struggled with early speech difficulties, the Albert Einstein Archives indicate he
excelled at the first school that he attended.[13] He was right-handed;[13][14] there
appears to be no evidence for the widespread popular belief [15] that he was lefthanded.
His father once showed him a pocket compass; Einstein realized that there must be
something causing the needle to move, despite the apparent "empty space". [16] As he
grew, Einstein built models and mechanical devices for fun and began to show a
talent for mathematics.[11] When Einstein was 10 years old, Max Talmud (later
changed to Max Talmey), a poor Jewish medical student from Poland, was
introduced to the Einstein family by his brother. During weekly visits over the next
five years, he gave the boy popular books on science, mathematical texts and
philosophical writings. These included Immanuel Kant's Critique of Pure Reason,
and Euclid's Elements (which Einstein called the "holy little geometry book").[17][18][fn 1]
In 1894, his father's company failed: direct current (DC) lost the War of
Currents to alternating current (AC). In search of business, the Einstein family moved
to Italy, first to Milan and then, a few months later, to Pavia. When the family moved
to Pavia, Einstein stayed in Munich to finish his studies at the Luitpold Gymnasium.
His father intended for him to pursue electrical engineering, but Einstein clashed with
authorities and resented the school's regimen and teaching method. He later wrote
that the spirit of learning and creative thought were lost in strict rote learning. At the
end of December 1894, he travelled to Italy to join his family in Pavia, convincing the
school to let him go by using a doctor's note.[20] It was during his time in Italy that he
wrote a short essay with the title "On the Investigation of the State of the Ether in a
Magnetic Field."[21][22]
In 1895, at the age of 16, Einstein sat the entrance examinations for the Swiss
Federal Polytechnic in Zürich (later the Eidgenössische Technische Hochschule
ETH). He failed to reach the required standard in the general part of the
examination,[23] but obtained exceptional grades in physics and mathematics.[24] On
the advice of the Principal of the Polytechnic, he attended the Argovian cantonal
school (gymnasium) in Aarau, Switzerland, in 1895–96 to complete his secondary
schooling. While lodging with the family of Professor Jost Winteler, he fell in love with
Winteler's daughter, Marie. (Albert's sister Maja later married Wintelers' son
Paul.)[25] In January 1896, with his father's approval, he renounced his citizenship in
the German Kingdom of Württemberg to avoid military service.[26] In September 1896,
he passed the Swiss Matura with mostly good grades, including a top grade of 6 in
physics and mathematical subjects, on a scale of 1–6,[27] and, though only 17,
enrolled in the four-year mathematics and physics teaching diploma program at the
Zürich Polytechnic. Marie Winteler moved to Olsberg, Switzerland for a teaching
post.
Einstein's future wife, Mileva Marić, also enrolled at the Polytechnic that same year,
the only woman among the six students in the mathematics and physics section of
the teaching diploma course. Over the next few years, Einstein and Marić's
friendship developed into romance, and they read books together on extra-curricular
physics in which Einstein was taking an increasing interest. In 1900, Einstein was
awarded the Zürich Polytechnic teaching diploma, but Marić failed the examination
with a poor grade in the mathematics component, theory of functions.[28] There have
been claims that Marić collaborated with Einstein on his celebrated 1905
papers,[29][30] but historians of physics who have studied the issue find no evidence
that she made any substantive contributions.[31][32][33][34]
Marriages and children
Albert Einstein in 1904
With the discovery and publication in 1987 of an early correspondence between
Einstein and Marić it became known that they had a daughter they called "Lieserl" in
their letters, born in early 1902 in Novi Sad where Marić was staying with her
parents. Marić returned to Switzerland without the child, whose real name and fate
are unknown. Einstein probably never saw his daughter, and the contents of a letter
he wrote to Marić in September 1903 suggest that she was either adopted or died
of scarlet fever in infancy.[35][36]
Elsa Einstein with her husband
Einstein and Marić married in January 1903. In May 1904, the couple's first
son, Hans Albert Einstein, was born in Bern, Switzerland. Their second son, Eduard,
was born in Zurich in July 1910. In 1914, Einstein moved to Berlin, while his wife
remained in Zurich with their sons. They divorced on 14 February 1919, having lived
apart for five years.
Einstein married Elsa Löwenthal on 2 June 1919, after having had a relationship with
her since 1912. She was his first cousin maternally and his second cousin paternally.
In 1933, they emigrated to the United States. In 1935, Elsa Einstein was diagnosed
with heart and kidney problems and died in December 1936.[37]
Patent office
Left to right: Conrad Habicht,Maurice Solovine and Einstein, who founded the Olympia Academy
After graduating, Einstein spent almost two frustrating years searching for a teaching
post. He acquired Swiss citizenship in February 1901,[38] but was not conscripted for
medical reasons. With the help of Marcel Grossmann's father Einstein secured a job
in Bern at the Federal Office for Intellectual Property, the patent office,[39] as an
assistant examiner.[40] He evaluated patent applications for a variety of devices
including a gravel sorter and an electromechanical typewriter.[41] In 1903, Einstein's
position at the Swiss Patent Office became permanent, although he was passed
over for promotion until he "fully mastered machine technology".[42]
Much of his work at the patent office related to questions about transmission of
electric signals and electrical-mechanical synchronization of time, two technical
problems that show up conspicuously in the thought experiments that eventually led
Einstein to his radical conclusions about the nature of light and the fundamental
connection between space and time.[43]
With a few friends he had met in Bern, Einstein started a small discussion group,
self-mockingly named "The Olympia Academy", which met regularly to discuss
science and philosophy. Their readings included the works of Henri Poincaré, Ernst
Mach, and David Hume, which influenced his scientific and philosophical outlook.
Academic career
Einstein's official 1921 portrait after receiving the Nobel Prize in Physics
In 1900, his paper "Folgerungen aus den Capillaritätserscheinungen" ("Conclusions
from the Capillarity Phenomena") was published in the prestigious Annalen der
Physik.[44][45] On 30 April 1905, Einstein completed his thesis, with Alfred Kleiner,
Professor of Experimental Physics, serving as pro-forma advisor. Einstein was
awarded a PhD by the University of Zürich. His dissertation was entitled "A New
Determination of Molecular Dimensions."[46][47] This paper included Einstein's initial
estimates of Avogadro constant as 2.2×1023 based on diffusion coefficients and
viscosities of sugar solutions in water.[48] That same year, which has been called
Einstein's annus mirabilis (miracle year), he published four groundbreaking papers,
on the photoelectric effect, Brownian motion, special relativity, and the equivalence
of mass and energy, which were to bring him to the notice of the academic world.
By 1908, he was recognized as a leading scientist, and he was appointed lecturer at
the University of Bern. In February 1909, he held a lecture on electrodynamics and
the relativity principle in the lecture hall of the Physics Institute of the University of
Zurich. Thereafter Alfred Kleinerrecommended him to the faculty for a newly created
professorship in theoretical physics. On May 7, 1909 the "Regierungsrat des
Kantons Zürich"appointed him associate professor from the 15 th October 1909 with
an annual salary of CHF 4500.[49] He became a full professor at Charles-Ferdinand
University in Prague in 1911. Also in 1911, corrections of algebraic errors in his
thesis brought Einstein's Avogadro constant estimate to6.6×1023. In 1912 Einstein
returned to his Alma Mater. From 1912 until 1914 he was appointed as professor for
theoretical physics at the ETH inZurich, where he taught analytical mechanics,
thermodynamics, and read about continuum mechanics and the molecular theory of
heat. During this time he was mainly concerned with the problem of gravitation,
which he attempted to solve in Zurich together with the mathematician Marcel
Grossmann.[50] In 1914, he returned to the German Empire after being appointed
director of the Kaiser Wilhelm Institute for Physics (1914–1932)[51]and a professor at
the Humboldt University of Berlin, with a special clause in his contract that freed him
from most teaching obligations. He became a member of the Prussian Academy of
Sciences. In 1916, Einstein was appointed president of the German Physical
Society (1916–1918).[52][53]
During 1911, he had calculated that, based on his new theory of general relativity,
light from another star would be bent by the Sun's gravity. That prediction was
claimed confirmed by observations made by a British expedition led by Sir Arthur
Eddington during the solar eclipse of 29 May 1919. International media reports of
this made Einstein world famous. On 7 November 1919, the leading British
newspaper The Times printed a banner headline that read: "Revolution in Science –
New Theory of the Universe – Newtonian Ideas Overthrown".[54]
In 1921, Einstein was awarded the Nobel Prize in Physics for his explanation of the
photoelectric effect, as relativity was considered still somewhat controversial. He
also received the Copley Medal from the Royal Society in 1925.[2]
Travels abroad, 1921–1922
Einstein in New York, 1921, his first visit to the United States
Einstein visited New York City for the first time on 2 April 1921, where he received an
official welcome by Mayor John Francis Hylan, followed by three weeks of lectures
and receptions. He went on to deliver several lectures at Columbia
University and Princeton University, and in Washington he accompanied
representatives of the National Academy of Science on a visit to the White House.
On his return to Europe he was the guest of the British statesman and
philosopher Viscount Haldane in London, where he met several renowned scientific,
intellectual and political figures, and delivered a lecture at King's College.[55]
He also published an essay, "My First Impression of the U.S.A.," in July 1921, in
which he tried briefly to describe some characteristics of Americans, much as Alexis
de Tocqueville did, who published his own impressions in Democracy in
America (1835).[56] For some of his observations, Einstein was clearly surprised:
"What strikes a visitor is the joyous, positive attitude to life . . . The American is
friendly, self-confident, optimistic, and without envy."[57]:20
In 1922, his travels took him to Asia and later to Palestine, as part of a six-month
excursion and speaking tour. He visited Singapore,Ceylon and Japan, where he
gave a series of lectures to thousands of Japanese. His first lecture in Tokyo lasted
four hours, after which he met the emperor and empress at the Imperial Palace,
where thousands came to watch. Einstein later gave his favorable impressions of the
Japanese in a letter to his sons.[58]:307[58]:308
On his return voyage, he also visited Palestine for 12 days in what would become his
only visit to that region. He was greeted as if a head of state rather than a theoretical
physicist, writes Isaacson. This included a cannon salute upon his arrival at the
residence of the British high commissioner, Sir Herbert Samuel. During one
reception given to him, the building was stormed by people who wanted to hear him.
In Einstein's talk to the audience, he expressed happiness that the Jewish people
were in the process of making themselves recognized as a force in the world. [59]:308
Travel to U.S., 1930–1931
In December 1930, Einstein visited America for the second time, originally intended
as a two-month working visit as a research fellow at the California Institute of
Technology. After the national attention he received during his first trip to the U.S.,
he and his arrangers aimed to protect his privacy. Although swamped with telegrams
and invitations to receive awards or speak publicly, he declined them all. [59]:368
Charlie Chaplin and Einstein at the Hollywood premier of City Lights, January 1931
After arriving in New York City, Einstein was taken to various places and events,
including Chinatown, a lunch with the editors of the New York Times, and a
performance of Carmen at the Metropolitan Opera, where he was cheered by the
audience on his arrival. During the days following, he was given the keys to the city
by Mayor Jimmy Walker and met the president of Columbia University, who
described Einstein as "the ruling monarch of the mind."[59]:370 Harry Emerson Fosdick,
pastor at New York's Riverside Church, gave Einstein a tour of the church and
showed him a full-size statue the church made of Einstein, standing at the
entrance.[59]:370 Also during his stay in New York, he joined a crowd of 15,000 people
at Madison Square Garden during a Hanukkah celebration.[59]:370
Einstein next traveled to California where he met Caltech president and Nobel
laureate, Robert A. Millikan. His friendship with Millikan was "awkward", as Millikan
"had a penchant for patriotic militarism," where Einstein was a pronounced
pacifist.[59]:373 During an address to Caltech's students, Einstein noted that science
was often inclined to do more harm than good.[59]:374
This aversion to war also led Einstein to befriend author Upton Sinclair and film
star Charlie Chaplin, both noted for their pacifism. Carl Laemmle, head of Universal
Studios, gave Einstein a tour of his studio and introduced him to Chaplin. They had
an instant rapport, with Chaplin inviting Einstein and his wife, Elsa, to his home for
dinner. Chaplin recalled Einstein as being amiable, calm, but with energy driven by
an underlying emotionality.[60]:320
Chaplin also remembers Elsa telling him about the time Einstein conceived
his theory of relativity. During breakfast one morning, he seemed lost in thought and
ignored his food. She asked him if something was bothering him. He sat down at his
piano and started playing. He continued playing and writing notes for half an hour,
then went upstairs to his study, where he remained for two weeks, with Elsa bringing
up his food. At the end of the two weeks he came downstairs with two sheets of
paper bearing his theory.[60]:320
Chaplin's film, City Lights, was to premier a few days later in Hollywood, and Chaplin
invited Einstein and Elsa to join him as his special guests. Considered by Isaacson
as "one of the most memorable scenes in the new era of celebrity," he describes the
event with "Einstein and Chaplin arriving together, dressed in black tie, with Elsa
beaming." They were applauded as they entered the theater.[59]:374 Chaplin visited
Einstein during a later trip to Berlin, and recalled his "modest little flat" and the piano
at which he had begun writing his theory. Chaplin speculated that it was "possibly
used as kindling wood by the Nazis."[60]:322
Emigration to U.S. in 1933
Cartoon of Einstein, who has shed his "Pacifism" wings, standing next to a pillar labeled "World
Peace." He is rolling up his sleeves and holding a sword labeled "Preparedness" (by Charles R.
Macauley, c. 1933).
In February 1933 while on a visit to the United States, Einstein knew he could not to
return to Germany with the rise to power of the Nazisunder Germany's new
chancellor, Adolf Hitler.[61][62]
While at American universities in early 1933, he undertook his third two-month
visiting professorship at the California Institute of Technologyin Pasadena. He and
his wife Elsa returned to Belgium by ship in March, and during the trip they learned
that their cottage was raided by the Nazis and his personal sailboat confiscated.
Upon landing in Antwerp on 28 March, he immediately went to the German
consulate and turned in his passport, formally renouncing his German
citizenship.[59] A few years later, the Nazis sold his boat and turned his cottage into an
Aryan youth camp.[63]
Refugee status
In April 1933, he also discovered that the new German government had passed laws
barring Jews from holding any official positions, including teaching at
universities.[59] Historian Gerald Holton describes how, with "virtually no audible
protest being raised by their colleagues," thousands of Jewish scientists were
suddenly forced to give up their university positions and their names were removed
from the rolls of institutions where they were employed.[57]
A month later, Einstein's works were among those targeted by Nazi book burnings,
with Nazi propaganda minister Joseph Goebbelsproclaiming, "Jewish intellectualism
is dead."[59] One German magazine included him in a list of enemies of the German
regime with the phrase, "not yet hanged", offering a "$5,000 bounty" on his
head.[59][64] In a subsequent letter to physicist and friend, Max Born, who had already
emigrated from Germany to England, Einstein wrote, "... I must confess that the
degree of their brutality and cowardice came as something of a surprise." [59] After
moving to the U.S., he described the book burnings as a "spontaneous emotional
outburst" by those who "shun popular enlightenment," and "more than anything else
in the world, fear the influence of men of intellectual independence." [65]:197
Einstein surrounded by Oliver Locker-Lampson (seated) and assistants assigned to protect him
Einstein was now without a permanent home, unsure where he would live and work,
and equally worried about the fate of countless other scientists still in Germany. He
rented a house in Belgium where he lived for a few months. In late July 1933, he
went to England for about six weeks at the personal invitation of British naval officer
Commander Oliver Locker-Lampson, who had become friends with Einstein in the
preceding years. To protect Einstein, Locker-Lampson secretly had two assistants
watch over him at his secluded cottage outside of London. A photo of them guarding
Einstein was published in the press.[59]:422
Locker-Lampson took Einstein to meet Winston Churchill at his home, and
later, Austen Chamberlain and former Prime Minister Lloyd George.[59]:419–420 Einstein
asked them to help bring Jewish scientists out of Germany. Churchill responded
immediately, notes British historian Martin Gilbert, and sent his friend,
physicist Frederick Lindemann to Germany to seek out Jewish scientists and place
them in British universities.[66] Churchill later declared that as a result of Germany
having driven the Jews out, they lowered their "technical standards," and had put the
Allies' technology ahead of theirs.[66]
Einstein later contacted leaders of other nations, including Turkey's Prime
Minister, İsmet İnönü, who he wrote in September 1933 requesting placement of
unemployed German-Jewish scientists. As a result of Einstein's letter, Jewish
invitees in 1933 numbered 30, later grew to over 190 scientists, and eventually
totaled over "1,000 saved individuals."[67]
Locker-Lampson submitted a bill to parliament that would have the effect of
extending British citizenship to Einstein, with Einstein then making a number of
public appearances to explain the crisis brewing in Europe. The bill failed to become
law, however, and Einstein then decided to accept an earlier offer he received from
the Princeton Institute for Advanced Study to be a resident scholar.[68]
Resident scholar at the Institute for Advanced Study
Portrait taken in 1935 in Princeton
In October 1933 he returned to the U.S. and took up a position at the Institute for
Advanced Study (in Princeton, New Jersey).[68][69] The institute had become a refuge
for scientists fleeing Nazi Germany.[70] At the time most American universities
including Harvard, Princeton and Yale, had minimal Jewish faculty and students as a
result of their Jewish quota, which lasted until the late 1940s, after WWII had
ended.[70]
He was still undecided on his future (he had offers from European universities,
including Oxford), but in 1935 he arrived at the decision to remain permanently in the
United States and apply for citizenship.[68][71]
His affiliation with the Institute for Advanced Study would last until his death in
1955.[72] He was one of the four first selected (two of the others being John von
Neumann and Kurt Gödel) at the new Institute, where he soon developed a close
friendship with Gödel. The two would take long walks together discussing their work.
His last assistant was Bruria Kaufman, who later became a physicist. During this
period, Einstein tried to develop a unified field theory and to refute the accepted
interpretation of quantum physics, both unsuccessfully.
Other scientists also fled to America. Among them were Nobel laureates and
professors of theoretical physics. With so many other Jewish scientists now forced
by circumstances to live in America, often working side by side, Einstein wrote "In my
whole life I have never felt so Jewish as now."[59]
World War II and the Manhattan Project
In 1939, a group of Hungarian scientists that included émigré physicist Leó
Szilárd attempted to alert Washington of ongoing Nazi atomic bomb research. The
group's warnings were discounted.[73] Einstein and Szilárd, along with other refugees
such as Edward Teller and Eugene Wigner, "regarded it as their responsibility to
alert Americans to the possibility that German scientists might win the race to build
an atomic bomb, and to warn that Hitler would be more than willing to resort to such
a weapon."[58]:630[74] On July 12, 1939, a few months before the beginning of World War
II in Europe, Szilárd and Wigner visited Einstein[75] and they explained the possibility
of atomic bombs, to which pacifist Einstein replied:Daran habe ich gar nicht
gedacht ("I had not thought of that at all").[76] Einstein was persuaded to lend his
prestige by writing a letter with Szilárd to President Franklin D. Rooseveltto alert him
of the possibility. The letter also recommended that the U.S. government pay
attention to and become directly involved in uranium research and associated chain
reaction research.
The letter is believed to be "arguably the key stimulus for the U.S. adoption of
serious investigations into nuclear weapons on the eve of the U.S. entry into World
War II".[77] In addition to the letter, Einstein used his connections with the Belgian
Royal Family[78] and the Belgian queen mother[73] to get access with a personal envoy
to the White House's Oval Office.[73] President Roosevelt could not take the risk of
allowing Hitler to possess atomic bombs first. As a result of Einstein's letter and his
meetings with Roosevelt, the U.S. entered the "race" to develop the bomb, drawing
on its "immense material, financial, and scientific resources" to initiate the Manhattan
Project. It became the only country to successfully develop an atomic bomb during
World War II.
For Einstein, "war was a disease ... [and] he called for resistance to war." By signing
the letter to Roosevelt he went against his pacifist principles.[79] In 1954, a year
before his death, Einstein said to his old friend, Linus Pauling, "I made one great
mistake in my life—when I signed the letter to President Roosevelt recommending
that atom bombs be made; but there was some justification—the danger that the
Germans would make them ..."[80]
US citizenship
Einstein accepting U.S. citizenshipcertificate from judge Phillip Forman
Einstein became an American citizen in 1940. Not long after settling into his career
at the Institute for Advanced Study (in Princeton, New Jersey), he expressed his
appreciation of the "meritocracy" in American culture when compared to Europe.
According to Isaacson, he recognized the "right of individuals to say and think what
they pleased", without social barriers, and as a result, the individual was
"encouraged" to be more creative, a trait he valued from his own early education.[59]:432
Einstein worked in 1943 and 1944 as a $25-per-day consultant to the Research and
Development Division of the U.S. Navy's Division of Ordnance.[81]
Personal life
Supporter of civil rights
Einstein was a passionate, committed antiracist and joined National Association for
the Advancement of Colored People (NAACP) in Princeton, where he campaigned
for the civil rights of African Americans. He considered racism America's "worst
disease,"[64] seeing it as "handed down from one generation to the next." [82] As part of
his involvement, he corresponded with civil rights activist W. E. B. Du Bois and was
prepared to testify on his behalf during his trial in 1951.[83]:565 When Einstein offered to
be a character witness for Du Bois, the judge decided to drop the case. [84]
Einstein in 1947
In 1946 Einstein visited Lincoln University in Pennsylvania where he was awarded
an honorary degree. Lincoln was the first university to grant college degrees to
blacks, including Langston Hughes and Thurgood Marshall. To its students, Einstein
gave a speech about racism in America, adding, "I do not intend to be quiet about
it."[84] A resident of Princeton recalls that Einstein had once paid the college tuition for
a black student,[84] and black physicist Sylvester James Gates states that Einstein
had been one of his early science heroes, later finding out about Einstein's support
for civil rights.[84]
Assisting Zionist causes
Einstein was a figurehead leader in helping establish Hebrew University of
Jerusalem, which opened in 1925, and was among its first Board of Governors.
Earlier, in 1921, he was asked by the president of the World Zionist
Organization, Chaim Weizmann, to help raise funds for the planned
university.[59]:290 He also submitted various suggestions as to its initial programs.
Among those, he advised first creating an Institute of Agriculture in order to settle the
undeveloped land. That should be followed, he suggested, by a Chemical Institute
and an Institute of Microbiology, to fight the various ongoing epidemics such
as malaria, which he called an "evil" that was undermining a third of the country's
development.[85]:161 Establishing an Oriental Studies Institute, to include language
courses given in both Hebrew and Arabic, for scientific exploration of the country and
its historical monuments, was also important.[85]:158
After the death of Israel's first president, Chaim Weizmann, in November 1952,
Prime Minister David Ben-Gurion offered Einstein the position of President of Israel,
a mostly ceremonial post.[86] The offer was presented by Israel's ambassador in
Washington, Abba Eban, who explained that the offer "embodies the deepest
respect which the Jewish people can repose in any of its sons". [58]:522 Einstein
declined, and wrote in his response that he was "deeply moved", and "at once
saddened and ashamed" that he could not accept it.[58]:522
Love of music
If I were not a physicist, I would probably be a musician. I often think in music. I live my
daydreams in music. I see my life in terms of music... I get most joy in life out of music.
Albert Einstein[87][88]
Einstein developed an appreciation of music at an early age. His mother played the
piano reasonably well and wanted her son to learn the violin, not only to instill in him
a love of music but also to help him assimilate German culture. According to
conductor Leon Botstein, Einstein is said to have begun playing when he was 5, but
did not enjoy it at that age.[89]
Albert Einstein playing violin
Einstein with musician and Nobel laureate Rabindranath Tagore, 1930
When he turned 13 he discovered the violin sonatas of Mozart. "Einstein fell in love"
with Mozart's music, notes Botstein, and learned to play music more willingly.
According to Einstein, he taught himself to play without "ever practicing
systematically", adding that "Love is a better teacher than a sense of duty." [89] At age
17, he was heard by a school examiner in Aarau as he played Beethoven's violin
sonatas, the examiner stating afterward that his playing was "remarkable and
revealing of 'great insight'." What struck the examiner, writes Botstein, was that
Einstein "displayed a deep love of the music, a quality that was and remains in short
supply. Music possessed an unusual meaning for this student." [89]
Botstein notes that music assumed a pivotal and permanent role in Einstein's life
from that period on. Although the idea of becoming a professional himself was not on
his mind at any time, among those with whom Einstein played chamber music were
a few professionals, and he performed for private audiences and friends. Chamber
music also became a regular part of his social life while living in Bern, Zürich, and
Berlin, where he played with Max Planck and his son, among others. In 1931, while
engaged in research at the California Institute of Technology, he visited the Zoellner
family conservatory in Los Angeles and played some of Beethoven and Mozart's
works with members of the Zoellner Quartet, recently retired from two decades of
acclaimed touring all across the United States; Einstein later presented the family
patriarch with an autographed photograph as a memento.[90][91] Near the end of his
life, when the young Juilliard Quartet visited him in Princeton, he played his violin
with them; although they slowed the tempo to accommodate his lesser technical
abilities, Botstein notes the quartet was "impressed by Einstein's level of
coordination and intonation."[89]
Political and religious views
Main articles: Albert Einstein's political views and Albert Einstein's religious views
Albert Einstein with his wife Elsa Einstein and Zionist leaders, including future President of
Israel Chaim Weizmann, his wife Vera Weizmann,Menahem Ussishkin, and Ben-Zion Mossinson
on arrival in New York City in 1921
Einstein's political view was in favor of socialism and critical of capitalism, which he
detailed in his essays such as "Why Socialism?".[92][93]Einstein offered and was called
on to give judgments and opinions on matters often unrelated to theoretical physics
or mathematics.[68]
Einstein's views about religious belief have been collected from interviews and
original writings.
He called himself an agnostic, while disassociating himself from the
label atheist.[94] He said he believed in the "pantheistic" God of Baruch Spinoza, but
not in a personal god, a belief he criticized.[95][96]
Death
On 17 April 1955, Albert Einstein experienced internal bleeding caused by the
rupture of an abdominal aortic aneurysm, which had previously been reinforced
surgically by Dr. Rudolph Nissen in 1948.[97] He took the draft of a speech he was
preparing for a television appearance commemorating the State of Israel's seventh
anniversary with him to the hospital, but he did not live long enough to complete it.[98]
Einstein refused surgery, saying: "I want to go when I want. It is tasteless to prolong
life artificially. I have done my share, it is time to go. I will do it elegantly." [99] He died
in Princeton Hospital early the next morning at the age of 76, having continued to
work until near the end.
During the autopsy, the pathologist of Princeton Hospital, Thomas Stoltz Harvey,
removed Einstein's brain for preservation without the permission of his family, in the
hope that the neuroscience of the future would be able to discover what made
Einstein so intelligent.[100]Einstein's remains were cremated and his ashes were
scattered at an undisclosed location.[101][102]
In his lecture at Einstein's memorial, nuclear physicist Robert
Oppenheimer summarized his impression of him as a person: "He was almost wholly
without sophistication and wholly without worldliness ... There was always with him a
wonderful purity at once childlike and profoundly stubborn." [103]
Scientific career
Throughout his life, Einstein published hundreds of books and articles. [9][11] In addition
to the work he did by himself he also collaborated with other scientists on additional
projects including the Bose–Einstein statistics, the Einstein refrigerator and others.[104]
1905 – Annus Mirabilis papers
Main articles: Annus Mirabilis papers, Photoelectric effect, Special theory of relativity, Mass–
energy equivalence and Brownian motion
The Annus Mirabilis papers are four articles pertaining to the photoelectric
effect (which gave rise to quantum theory), Brownian motion, the special theory of
relativity, and E = mc2that Albert Einstein published in the Annalen der
Physik scientific journal in 1905. These four works contributed substantially to the
foundation of modern physics and changed views on space, time, and matter. The
four papers are:
Title (translated)
Area of
focus
Received Published
Significance
Resolved an unsolved puzzle by
On a Heuristic
suggesting that energy is
Viewpoint
Concerning the
Photoelectric
Production and
effect
exchanged only in discrete
18 March
9 June
amounts (quanta).[105] This idea
was pivotal to the early
Transformation of
development of quantum
Light
theory.[106]
On the Motion of
Small Particles
Suspended in a
Stationary Liquid,
as Required by the
Molecular Kinetic
Theory of Heat
Brownian
motion
Explained empirical evidence for
11 May
18 July
the atomic theory, supporting the
application of statistical physics.
Reconciled Maxwell's equations
for electricity and magnetism
with the laws of mechanics by
introducing major changes to
On the
Electrodynamics of
Moving Bodies
mechanics close to the speed of
Special
relativity
30 June
26
light, resulting from analysis
September based on empirical evidence that
the speed of light is independent
of the motion of the
observer.[107]Discredited the
concept of a "luminiferous
ether."[108]
Equivalence of matter and
Does the Inertia of
a Body Depend
Upon Its Energy
Content?
Matter–
energy
equivalence
energy, E = mc2 (and by
27
21
implication, the ability of gravity
September November to "bend" light), the existence of
"rest energy", and the basis of
nuclear energy.
Thermodynamic fluctuations and statistical physics
Main articles: Statistical mechanics, thermal fluctuations and statistical physics
Albert Einstein's first paper[109] submitted in 1900 to Annalen der Physik was
on capillary attraction. It was published in 1901 with the title "Folgerungen aus den
Capillaritätserscheinungen", which translates as "Conclusions from the capillarity
phenomena". Two papers he published in 1902–1903 (thermodynamics) attempted
to interpretatomic phenomena from a statistical point of view. These papers were the
foundation for the 1905 paper on Brownian motion, which showed that Brownian
movement can be construed as firm evidence that molecules exist. His research in
1903 and 1904 was mainly concerned with the effect of finite atomic size on diffusion
phenomena.[109]
General principles
He articulated the principle of relativity. This was understood by Hermann
Minkowski to be a generalization of rotational invariance from space to space-time.
Other principles postulated by Einstein and later vindicated are the principle of
equivalence and the principle of adiabatic invariance of the quantum number.
Theory of relativity and E = mc²
Main article: History of special relativity
Einstein's "Zur Elektrodynamik bewegter Körper" ("On the Electrodynamics of
Moving Bodies") was received on 30 June 1905 and published 26 September of that
same year. It reconciles Maxwell's equations for electricity and magnetism with the
laws of mechanics, by introducing major changes to mechanics close to the speed of
light. This later became known as Einstein's special theory of relativity.
Consequences of this include the time-space frame of a moving body appearing
to slow down and contract (in the direction of motion) when measured in the frame of
the observer. This paper also argued that the idea of a luminiferous aether—one of
the leading theoretical entities in physics at the time—was superfluous.[110]
In his paper on mass–energy equivalence, Einstein produced E = mc2 from his
special relativity equations.[111] Einstein's 1905 work on relativity remained
controversial for many years, but was accepted by leading physicists, starting
with Max Planck.[112][113]
Photons and energy quanta
The photoelectric effect. Incoming photons on the left strike a metal plate (bottom), and eject
electrons, depicted as flying off to the right.
Main articles: Photon and Quantum
In a 1905 paper,[114] Einstein postulated that light itself consists of localized particles
(quanta). Einstein's light quanta were nearly universally rejected by all physicists,
including Max Planck and Niels Bohr. This idea only became universally accepted in
1919, with Robert Millikan's detailed experiments on the photoelectric effect, and
with the measurement of Compton scattering.
Einstein concluded that each wave of frequency f is associated with a collection
of photons with energy hf each, where h is Planck's constant. He does not say much
more, because he is not sure how the particles are related to the wave. But he does
suggest that this idea would explain certain experimental results, notably the
photoelectric effect.[115]
Quantized atomic vibrations
Main article: Einstein solid
In 1907, Einstein proposed a model of matter where each atom in a lattice structure
is an independent harmonic oscillator. In the Einstein model, each atom oscillates
independently—a series of equally spaced quantized states for each oscillator.
Einstein was aware that getting the frequency of the actual oscillations would be
different, but he nevertheless proposed this theory because it was a particularly clear
demonstration that quantum mechanics could solve the specific heat problem in
classical mechanics. Peter Debye refined this model.[116]
Adiabatic principle and action-angle variables
Main article: Old quantum theory
Throughout the 1910s, quantum mechanics expanded in scope to cover many
different systems. After Ernest Rutherford discovered the nucleus and proposed that
electrons orbit like planets, Niels Bohr was able to show that the same quantum
mechanical postulates introduced by Planck and developed by Einstein would
explain the discrete motion of electrons in atoms, and the periodic table of the
elements.
Einstein contributed to these developments by linking them with the 1898
arguments Wilhelm Wien had made. Wien had shown that the hypothesis
of adiabatic invariance of a thermal equilibrium state allows all the blackbody
curves at different temperature to be derived from one another by a simple shifting
process. Einstein noted in 1911 that the same adiabatic principle shows that the
quantity which is quantized in any mechanical motion must be an adiabatic
invariant. Arnold Sommerfeld identified this adiabatic invariant as theaction
variable of classical mechanics.
Wave–particle duality
Einstein during his visit to the United States
Main article: Wave–particle duality
Although the patent office promoted Einstein to Technical Examiner Second Class in
1906, he had not given up on academia. In 1908, he became aPrivatdozent at the
University of Bern.[117] In "über die Entwicklung unserer Anschauungen über das
Wesen und die Konstitution der Strahlung" ("The Development of our Views on the
Composition and Essence of Radiation"), on the quantization of light, and in an
earlier 1909 paper, Einstein showed that Max Planck's energy quanta must have
well-defined momenta and act in some respects as independent, point-like particles.
This paper introduced the photon concept (although the name photon was
introduced later by Gilbert N. Lewis in 1926) and inspired the notion of wave–particle
duality in quantum mechanics. Einstein saw this wave-particle duality in radiation as
concrete evidence for his conviction that physics needed a new, unified foundation.
Theory of critical opalescence
Main article: Critical opalescence
Einstein returned to the problem of thermodynamic fluctuations, giving a treatment of
the density variations in a fluid at its critical point. Ordinarily the density fluctuations
are controlled by the second derivative of the free energy with respect to the density.
At the critical point, this derivative is zero, leading to large fluctuations. The effect of
density fluctuations is that light of all wavelengths is scattered, making the fluid look
milky white. Einstein relates this to Rayleigh scattering, which is what happens when
the fluctuation size is much smaller than the wavelength, and which explains why the
sky is blue.[118] Einstein quantitatively derived critical opalescence from a treatment of
density fluctuations, and demonstrated how both the effect and Rayleigh scattering
originate from the atomistic constitution of matter.
Zero-point energy
Main article: Zero-point energy
Einstein's physical intuition led him to note that Planck's oscillator energies had an
incorrect zero point. He modified Planck's hypothesis by stating that the lowest
energy state of an oscillator is equal to 1⁄2hf, to half the energy spacing between
levels. This argument, which was made in 1913 in collaboration with Otto Stern, was
based on the thermodynamics of a diatomic molecule which can split apart into two
free atoms.
General relativity and the equivalence principle
Main article: History of general relativity
See also: Principle of equivalence, Theory of relativity and Einstein field equations
Eddington's photograph of a solar eclipse
General relativity (GR) is a theory of gravitation that was developed by Albert
Einstein between 1907 and 1915. According to general relativity, the observed
gravitational attraction between masses results from the warping of space and
time by those masses. General relativity has developed into an essential tool in
modern astrophysics. It provides the foundation for the current understanding
of black holes, regions of space where gravitational attraction is so strong that not
even light can escape.
As Albert Einstein later said, the reason for the development of general relativity was
that the preference of inertial motions within special relativitywas unsatisfactory,
while a theory which from the outset prefers no state of motion (even accelerated
ones) should appear more satisfactory.[119]Consequently, in 1908 he published an
article on acceleration under special relativity. In that article, he argued that free
fall is really inertial motion, and that for a free-falling observer the rules of special
relativity must apply. This argument is called the equivalence principle. In the same
article, Einstein also predicted the phenomenon of gravitational time dilation. In
1911, Einstein published another article expanding on the 1907 article, in which
additional effects such as the deflection of light by massive bodies were predicted.
Hole argument and Entwurf theory
Main article: Hole argument
While developing general relativity, Einstein became confused about the gauge
invariance in the theory. He formulated an argument that led him to conclude that a
general relativistic field theory is impossible. He gave up looking for fully generally
covariant tensor equations, and searched for equations that would be invariant under
general linear transformations only.
In June 1913, the Entwurf ("draft") theory was the result of these investigations. As
its name suggests, it was a sketch of a theory, with the equations of motion
supplemented by additional gauge fixing conditions. Simultaneously less elegant and
more difficult than general relativity, after more than two years of intensive work
Einstein abandoned the theory in November 1915 after realizing that the hole
argument was mistaken.[120]
Cosmology
Main article: Cosmology
In 1917, Einstein applied the general theory of relativity to model the structure of the
universe as a whole. He apprehended that his equations predicted the universe to be
either contracting or expanding. He wanted the universe to be eternal and
unchanging, but this type of universe is not consistent with relativity. To fix this,
Einstein modified the general theory by introducing a new notion, the cosmological
constant, which he called ''Lambda''.[121] The purpose of Lambda was to rectify the
effects of gravity and allow the whole system to stay balanced. With a positive
cosmological constant, the universe could be an eternal static sphere. However, in
1929, Edwin Hubble confirmed that the universe is expanding, Einstein exclaimed
after his Mount Wilson visit with Hubble: "If there is no quasi-static world, then away
with the cosmological term!"[122][123] and Einstein supposedly discarded the
cosmological constant.
Einstein believed a spherical static universe is philosophically preferred, because it
would obey Mach's principle. He had shown that general relativity incorporates
Mach's principle to a certain extent in frame dragging by gravitomagnetic fields, but
he knew that Mach's idea would not work if space goes on forever. In a closed
universe, he believed that Mach's principle would hold. Mach's principle has
generated much controversy over the years.
In many of Einstein biographies, writers claim that he called the creation of Lambda
his "biggest blunder". Recently, astrophysicist Mario Livio showed that Einstein
possibly never said that.[124] Instead of discarding Lambda, Einstein was continually
experimenting with it.[125]
In late 2013, Irish physicist Cormac O'Raifeartaigh, happened to discover a
handwritten manuscript by Einstein which was since then overlooked by other
scientists. The research paper was titled ''"Zum kosmologischen Problem"'' ("About
the Cosmological Problem").[126][127] And Einstein proposed a revision of his model, still
with a cosmological constant, but now the constant was responsible for the creation
of new matter as the universe expanded. Thus, the average density of the system
never changed. He stated in the paper, ''"In what follows, I would like to draw
attention to a solution to equation (1) that can account for Hubbel's [sic] facts, and in
which the density is constant over time." And: "If one considers a physically bounded
volume, particles of matter will be continually leaving it. For the density to remain
constant, new particles of matter must be continually formed in the volume from
space."''
This is consistent with the now-obsolete Steady State model of cosmology, proposed
later in 1949, and with today's modern understanding of dark energy.[128]
Modern quantum theory
Main article: Schrödinger equation
Newspaper headline on May 4, 1935
Einstein was displeased with quantum theory and mechanics (the very theory he
helped create), despite its acceptance by other physicists, stating that God "is not
playing at dice."[129] Einstein continued to maintain his disbelief in the theory, and
attempted unsuccessfully to disprove it until he died at the age of 76. [130] In 1917, at
the height of his work on relativity, Einstein published an article in Physikalische
Zeitschrift that proposed the possibility of stimulated emission, the physical process
that makes possible the maser and the laser.[131] This article showed that the statistics
of absorption and emission of light would only be consistent with Planck's distribution
law if the emission of light into a mode with n photons would be enhanced
statistically compared to the emission of light into an empty mode. This paper was
enormously influential in the later development of quantum mechanics, because it
was the first paper to show that the statistics of atomic transitions had simple laws.
Einstein discovered Louis de Broglie's work, and supported his ideas, which were
received skeptically at first. In another major paper from this era, Einstein gave a
wave equation for de Broglie waves, which Einstein suggested was the Hamilton–
Jacobi equation of mechanics. This paper would inspire Schrödinger's work of 1926.
Bose–Einstein statistics
Main article: Bose–Einstein statistics
In 1924, Einstein received a description of a statistical model from Indian
physicist Satyendra Nath Bose, based on a counting method that assumed that light
could be understood as a gas of indistinguishable particles. Einstein noted that
Bose's statistics applied to some atoms as well as to the proposed light particles,
and submitted his translation of Bose's paper to the Zeitschrift für Physik. Einstein
also published his own articles describing the model and its implications, among
them the Bose–Einstein condensate phenomenon that some particulates should
appear at very low temperatures.[132]It was not until 1995 that the first such
condensate was produced experimentally by Eric Allin Cornell and Carl
Wieman using ultra-cooling equipment built at the NIST–JILAlaboratory at
the University of Colorado at Boulder.[133] Bose–Einstein statistics are now used to
describe the behaviors of any assembly of bosons. Einstein's sketches for this
project may be seen in the Einstein Archive in the library of the Leiden University. [104]
Energy momentum pseudotensor
Main article: Stress-energy-momentum pseudotensor
General relativity includes a dynamical spacetime, so it is difficult to see how to
identify the conserved energy and momentum. Noether's theorem allows these
quantities to be determined from a Lagrangian with translation invariance,
but general covariance makes translation invariance into something of a gauge
symmetry. The energy and momentum derived within general relativity by Noether's
presecriptions do not make a real tensor for this reason.
Einstein argued that this is true for fundamental reasons, because the gravitational
field could be made to vanish by a choice of coordinates. He maintained that the
non-covariant energy momentum pseudotensor was in fact the best description of
the energy momentum distribution in a gravitational field. This approach has been
echoed by Lev Landau andEvgeny Lifshitz, and others, and has become standard.
The use of non-covariant objects like pseudotensors was heavily criticized in 1917
by Erwin Schrödinger and others.
Unified field theory
Main article: Classical unified field theories
Following his research on general relativity, Einstein entered into a series of attempts
to generalize his geometric theory of gravitation to include electromagnetism as
another aspect of a single entity. In 1950, he described his "unified field theory" in
a Scientific American article entitled "On the Generalized Theory of
Gravitation".[134] Although he continued to be lauded for his work, Einstein became
increasingly isolated in his research, and his efforts were ultimately unsuccessful. In
his pursuit of a unification of the fundamental forces, Einstein ignored some
mainstream developments in physics, most notably the strong and weak nuclear
forces, which were not well understood until many years after his death. Mainstream
physics, in turn, largely ignored Einstein's approaches to unification. Einstein's
dream of unifying other laws of physics with gravity motivates modern quests for
a theory of everything and in particular string theory, where geometrical fields
emerge in a unified quantum-mechanical setting.
Wormholes
Main article: Wormhole
Einstein collaborated with others to produce a model of a wormhole. His motivation
was to model elementary particles with charge as a solution of gravitational field
equations, in line with the program outlined in the paper "Do Gravitational Fields play
an Important Role in the Constitution of the Elementary Particles?". These solutions
cut and pastedSchwarzschild black holes to make a bridge between two patches.
If one end of a wormhole was positively charged, the other end would be negatively
charged. These properties led Einstein to believe that pairs of particles and
antiparticles could be described in this way.
Einstein–Cartan theory
Main article: Einstein–Cartan theory
Einstein at his office,University of Berlin, 1920
In order to incorporate spinning point particles into general relativity, the affine
connection needed to be generalized to include an antisymmetric part, called
the torsion. This modification was made by Einstein and Cartan in the 1920s.
Equations of motion
Main article: Einstein–Infeld–Hoffmann equations
The theory of general relativity has a fundamental law—the Einstein equations which
describe how space curves, the geodesic equation which describes how particles
move may be derived from the Einstein equations.
Since the equations of general relativity are non-linear, a lump of energy made out of
pure gravitational fields, like a black hole, would move on a trajectory which is
determined by the Einstein equations themselves, not by a new law. So Einstein
proposed that the path of a singular solution, like a black hole, would be determined
to be a geodesic from general relativity itself.
This was established by Einstein, Infeld, and Hoffmann for pointlike objects without
angular momentum, and by Roy Kerr for spinning objects.
Other investigations
Main article: Einstein's unsuccessful investigations
Einstein conducted other investigations that were unsuccessful and abandoned.
These pertain to force, superconductivity, gravitational waves, and other research.
Collaboration with other scientists
The 1927 Solvay Conference in Brussels, a gathering of the world's top physicists. Einstein in the
center.
In addition to longtime collaborators Leopold Infeld, Nathan Rosen, Peter
Bergmann and others, Einstein also had some one-shot collaborations with various
scientists.
Einstein–de Haas experiment
Main article: Einstein–de Haas effect
Einstein and De Haas demonstrated that magnetization is due to the motion of
electrons, nowadays known to be the spin. In order to show this, they reversed the
magnetization in an iron bar suspended on a torsion pendulum. They confirmed that
this leads the bar to rotate, because the electron's angular momentum changes as
the magnetization changes. This experiment needed to be sensitive, because the
angular momentum associated with electrons is small, but it definitively established
that electron motion of some kind is responsible for magnetization.
Schrödinger gas model
Einstein suggested to Erwin Schrödinger that he might be able to reproduce the
statistics of a Bose–Einstein gas by considering a box. Then to each possible
quantum motion of a particle in a box associate an independent harmonic oscillator.
Quantizing these oscillators, each level will have an integer occupation number,
which will be the number of particles in it.
This formulation is a form of second quantization, but it predates modern quantum
mechanics. Erwin Schrödinger applied this to derive the thermodynamic properties of
asemiclassical ideal gas. Schrödinger urged Einstein to add his name as co-author,
although Einstein declined the invitation.[135]
Einstein refrigerator
Main article: Einstein refrigerator
In 1926, Einstein and his former student Leó Szilárd co-invented (and in 1930,
patented) the Einstein refrigerator. This absorption refrigerator was then
revolutionary for having no moving parts and using only heat as an input. [136] On 11
November 1930, U.S. Patent 1,781,541 was awarded to Albert Einstein and Leó
Szilárd for the refrigerator. Their invention was not immediately put into commercial
production, as the most promising of their patents were quickly bought up by the
Swedish company Electrolux to protect its refrigeration technology from
competition.[137]
Bohr versus Einstein
Main article: Bohr–Einstein debates
Einstein and Niels Bohr, 1925
The Bohr–Einstein debates were a series of public disputes about quantum
mechanics between Albert Einstein and Niels Bohr who were two of its founders.
Their debates are remembered because of their importance to the philosophy of
science.[138][139][140]
Einstein–Podolsky–Rosen paradox
Main article: EPR paradox
In 1935, Einstein returned to the question of quantum mechanics. He considered
how a measurement on one of two entangled particles would affect the other. He
noted, along with his collaborators, that by performing different measurements on the
distant particle, either of position or momentum, different properties of the entangled
partner could be discovered without disturbing it in any way.
He then used a hypothesis of local realism to conclude that the other particle had
these properties already determined. The principle he proposed is that if it is possible
to determine what the answer to a position or momentum measurement would be,
without in any way disturbing the particle, then the particle actually has values of
position or momentum.
This principle distilled the essence of Einstein's objection to quantum mechanics. As
a physical principle, it was shown to be incorrect when theAspect experiment of 1982
confirmed Bell's theorem, which had been promulgated in 1964.
Non-scientific legacy
While traveling, Einstein wrote daily to his wife Elsa and adopted stepdaughters
Margot and Ilse. The letters were included in the papers bequeathed to The Hebrew
University. Margot Einstein permitted the personal letters to be made available to the
public, but requested that it not be done until twenty years after her death (she died
in 1986[141]). Barbara Wolff, of The Hebrew University's Albert Einstein Archives, told
the BBC that there are about 3,500 pages of private correspondence written
between 1912 and 1955.[142]
Corbis, successor to The Roger Richman Agency, licenses the use of his name and
associated imagery, as agent for the university.[143]
In popular culture
Main article: Albert Einstein in popular culture
In the period before World War II, the New York Times published a vignette in their
"The Talk of the Town" feature saying that Einstein was so well known in America
that he would be stopped on the street by people wanting him to explain "that
theory". He finally figured out a way to handle the incessant inquiries. He told his
inquirers "Pardon me, sorry! Always I am mistaken for Professor Einstein."[144]
Einstein has been the subject of or inspiration for many novels, films, plays, and
works of music.[145] He is a favorite model for depictions of mad scientists and absentminded professors; his expressive face and distinctive hairstyle have been widely
copied and exaggerated. Time magazine's Frederic Golden wrote that Einstein was
"a cartoonist's dream come true".[146]
Awards and honors
Main article: Einstein's awards and honors
Einstein received numerous awards and honors, including the Nobel Prize in
Physics.
Publications
The following publications by Albert Einstein are referenced in this article. A more
complete list of his publications may be found at List of scientific publications by
Albert Einstein.

Einstein, Albert (1901), "Folgerungen aus den Capillaritätserscheinungen
(Conclusions Drawn from the Phenomena of Capillarity)", Annalen der Physik 4 (3):
513,Bibcode:1901AnP...309..513E, doi:10.1002/andp.19013090306
 Einstein, Albert (1905a), "Über einen die Erzeugung und Verwandlung des Lichtes
betreffenden heuristischen Gesichtspunkt (On a Heuristic Viewpoint Concerning the
Production and Transformation of Light)", Annalen der Physik 17 (6): 132–
148,Bibcode:1905AnP...322..132E, doi:10.1002/andp.19053220607 This annus

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

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

mirabilis paper on the photoelectric effect was received by Annalen der Physik 18
March.
Einstein, Albert (1905b), A new determination of molecular dimensions. This PhD
thesis was completed 30 April and submitted 20 July.
Einstein, Albert (1905c), "On the Motion – Required by the Molecular Kinetic Theory
of Heat – of Small Particles Suspended in a Stationary Liquid", Annalen der
Physik 17 (8): 549–
560,Bibcode:1905AnP...322..549E, doi:10.1002/andp.19053220806. This annus
mirabilis paper on Brownian motion was received 11 May.
Einstein, Albert (1905d), "On the Electrodynamics of Moving Bodies", Annalen der
Physik 17(10): 891–
921, Bibcode:1905AnP...322..891E, doi:10.1002/andp.19053221004. This annus
mirabilis paper on special relativity was received 30 June.
Einstein, Albert (1905e), "Does the Inertia of a Body Depend Upon Its Energy
Content?",Annalen der Physik 18 (13): 639–
641, Bibcode:1905AnP...323..639E,doi:10.1002/andp.19053231314. This annus
mirabilis paper on mass-energy equivalence was received 27 September.
Einstein, Albert (1915), "Die Feldgleichungen der Gravitation (The Field Equations of
Gravitation)", Königlich Preussische Akademie der Wissenschaften: 844–847
Einstein, Albert (1917a), "Kosmologische Betrachtungen zur allgemeinen
Relativitätstheorie (Cosmological Considerations in the General Theory of
Relativity)", Königlich Preussische Akademie der Wissenschaften
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papers on this topic.
Einstein, Albert (1926), "Die Ursache der Mäanderbildung der Flussläufe und des
sogenannten Baerschen Gesetzes", Die Naturwissenschaften 14 (11): 223–
224,Bibcode:1926NW.....14..223E, doi:10.1007/BF01510300. On Baer's
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
Einstein, Albert (1979), Autobiographical Notes, Paul Arthur Schilpp (Centennial ed.),
Chicago: Open Court, ISBN 0-87548-352-6. The chasing a light beam thought
experiment is described on pages 48–51.
 Collected Papers: Stachel, John, Martin J. Klein, a. J. Kox, Michel Janssen, R.
Schulmann, Diana Komos Buchwald and others (Eds.) (1987–2006), The Collected
Papers of Albert Einstein, Vol. 1–10, Princeton University Press Further information
about the volumes published so far can be found on the webpages of the Einstein
Papers Project and on thePrinceton University Press Einstein Page
Notes
1. Jump up^ "Albert's intellectual growth was strongly fostered at home. His mother, a
talented pianist, ensured the children's musical education. His father regularly read
Schiller and Heine aloud to the family. Uncle Jakob challenged Albert with
mathematical problems, which he solved with 'a deep feeling of happiness'." More
significant were the weekly visits of Max Talmud from 1889 through 1894 during
which time he introduced the boy to popular scientific texts that brought to an end a
short-lived religious phase, convincing him that 'a lot in the Bible stories could not be
true'. A textbook of plane geometry that he quickly worked through led on to an avid
self-study of mathematics, several years ahead of the school curriculum.